If you suspect that there may be a problem with the Enterprise Vault system mailbox, work through this section.
To create the mailbox when it does not exist
Right-click the Users container and then, on the context menu, click New > User.
In the Full name box, type a name such as EV System mailbox for server, where server is the name of the Exchange server.
Uncheck Account is disabled. It does not matter what the other settings are.
Click Finish to create the user and mailbox.
Note that it may take some time for the mailbox to be available.